Devices and methods are provided for an improved motor stator. Diffusion plates diffuse the respective light beams scanned in the 2-dimensional direction to introduce them to corresponding spatial light modulation elements. In addition to the primary transport system 4, the fairground ride 1 has a secondary transport system 9. An alarm threshold is set based on the determined average and the standard deviation. The hollow-fiber porous membrane obtained is excellent in mechanical strength represented by tensile strength and elongation at break and in chemical resistance.